1. Field of the Invention
The present invention relates to ophthalmic instruments for use in cataract surgery. More particularly, the invention relates to an instrument which is usable to remove the natural lens from the eye, and which may also provide irrigation to the eye and aspiration of irrigation liquid and fragments of the fractured natural lens during surgery.
2. Related Technology
During ophthalmic surgery, it is often necessary to perform various functions within the eye. For example, during cataract surgery, these functions include breaking up of the natural lens of the eye, irrigating the eye and aspirating the natural lens particles and irrigation liquid from the eye.
A conventional device for breaking up the natural cataractogenious lens is a phacoemulsifier. This device uses a tubular cutting tip vibrated by ultrasonic energy and centrally provided with vacuum aspiration to remove the natural lens in fragments. However, the conventional phacoemulsifier has a significant risk of damage to surrounding eye tissues because of the vigor of its action.
To carry out surgical procedures within the eye, it is necessary to make one or more incisions in the eye. To minimize trauma and to speed the healing process, it is desirable that the incisions be as small as possible. The ophthalmic instruments are then inserted through the incisions into the interior of the eye. Once inserted, it is desirable to limit movement of the instruments at the sclera and the posterior capsule to calm the eye. Unfortunately, restricting movement of the instruments within the eye is often inconsistent with the task that the surgical instruments must perform. In addition, the function to be performed may require movement of the tip of the instrument (such as the cutting and aspirating tip of the phacoemulsifier) to various different locations in the eye, some of which are relatively inaccessible. Because of the vigorous action of the conventional phacoemulsifier, surrounding eye tissues which may be inadvertently contacted by this tip during movements of the instrument in the eye are at risk of damage or destruction.
It would be desirable to provide ophthalmic surgeons with an instrument capable of easily removing the natural cataractogenious lens via a small incision, but which is easier to control and less likely to do damage to surrounding tissues than the conventional phacoemulsifier.